KR100887460B1 - Composite building material - Google Patents

Abstract

The present invention generally relates to a composite building material comprising a lightweight core and a thin fiber cement surface material on one side of the core and a second surface material on the other side. The fiber cement surface material used for at least one of the surfaces of the building material is preferably 3/16 "or less, more preferably 1/8" or less. The raw fiber cement surface material is preferably molded by the slurry dehydration method to form a sheet in a fired, uncured state prior to the manufacture of the composite material. The composite building material is preferably assembled in an uncured state and then cured.

Composite building materials, lightweight cores, fiber cement, surface materials,

Description

Composite building material {COMPOSITE BUILDING MATERIAL}             

Background of the Invention

The present invention relates to a building material comprising a composite building material, more particularly a lightweight core and at least one fiber cement sheath formed on both sides of the core.

Fiber reinforced cement products, such as water resistant building sheets, have been used for construction since 1895. Recently, reinforcing fibers used in such products include asbestos fibers as well as cellulose (wood) fibers (Australian Patent AU 515151), metal fibers, glass fibers or other natural fibers. Typically, the density of such building sheets is 1.2-1.7 g / cm 3, and the density change can typically be made by varying the amount of fibers used also by compression and dehydration of the fiber cement slurry used in the manufacture.

The density of the fiber cements described above is heavier than wood products of the same dimensions and is more difficult to cut, machine and nail than wood and wood products. The density of the lumber is 0.7-0.9 g / cm 3 for dry hardwood and 0.38-0.6 g / cm 3 for dry softwood. Thus, fiber cement materials of similar density to the material make it possible to produce products that are lighter, easier to nail, cut and machine, while retaining the durability, fire resistance, corrosion resistance and water resistance of the fiber cement.

Summary of the Invention

Fiber cement building materials are typically installed on the exterior of building facades. The outer surface of the fiber cement product is exposed to local climatic conditions and subjected to stress caused by temperature and humidity changes, UV exposure, and exposure to pollutants and carbon dioxide in the atmosphere. Along with the modified cores to provide the composite material with one or more special properties, there is a need for building products having the outer durability, planar strength and moisture breakdown resistance of fiber cement on the outer surface. Special properties include, but are not limited to:

Light weight, for easy handling of full length and long length products

Ease of cutting similar to gypsum wallboard, which allows for quick and easy installation of products by calibrating and cutting with a utility knife;

Low thermal conductivity to insulate walls in building structures from external environmental conditions,

Flame insulation and low heat shrinkage to prevent heat and flame propagation through building walls and ceilings,

Low moisture permeability to direct and control water and moisture penetration and moisture flow into building walls, ceilings and roofs;

Low acoustic propagation and high acoustic absorption to reduce noise propagation through rooms in buildings.                 

Desired properties can be obtained with a sandwich composite design using fiber cement surface material on a core having a composition that is compatible with the properties.

The present invention generally relates to a composite building material comprising, in one embodiment, a lightweight core and a thin fiber cement surface material or fiber cement skin bonded to one side of the core and a second surface material bonded to the other side. The fiber cement surface material used for at least one of the surfaces of the building material preferably has a thickness of less than about 3/16 ", more preferably less than about 1/8". The thinner sheath provides an overall lightweight composite material because the sheath material has a higher density than the core material. The fiber cement surface material is preferably in a preformed (uncured) state at the time of assembling the shell and core into the sandwich composite material.

The object of the present invention is not limited, but may be specially designed for applications such as tile supports, wallboards, wall panels, siding, trims, coverings, deckings, floor finishes, structural members, fences, roofs, roof deckings or supports thereof. To produce composite building materials that can The size of the physical properties (strength, durability, etc.) can be altered by changing the composition of the surface material and / or the core. Composite materials having specially set mechanical properties can be produced by appropriately selecting the surface material and thickness. The density of the composite material can be reduced by foaming the core slurry and / or adding low density fillers. The uncured fiber cement surface material is preformed and preferably has a continuous length. The use of the preformed fiber cement surface material of the continuous sheet simplifies the manufacture of the composite material because it only casts the core composition instead of casting each of the core and surface material. In addition, the use of preformed fiber cement surface material of the continuous sheet eliminates the need for a separate carrier sheet.

Another object of the present invention is to produce composite materials with improved properties by co-curing the core and the surface material. Fabrication with an uncured fiber cement sheet provides greater flexibility in surface texture, surface contour, corner contour and composite material properties. The core slurry penetrates into the uncured fiber cement surface material and the co-curing of the core and the shell thereafter forms excellent interlayer bonds, resulting in interpenetrating mechanical and chemical bonds. The bonding can be further improved by a cementic bonding layer applied to the core side of the surface material. The interlayer bonding is improved by controlling the water content and / or prehardness of the raw sheet so that the core slurry can fully penetrate the pore network of the sheet. This makes the mechanical fixation and chemical bonding stronger after curing. In addition, antifoams, thickeners or other additives in the uncured surface material may be used to break bubbles at the surface material-core interface. This leads to the formation of a dense interlayer by increasing the contact surface area between the core and the surface material. This suppresses the occurrence of delamination which greatly reduces the strength and durability of the composite material.

In one aspect of the invention, a building material is provided that includes at least a first component and a second component provided adjacent to the first component. The first component is provided as preformed uncured fiber cement, the fiber cement being reinforced with individualized fibers. The uncured fiber cement is cured after providing the first component adjacent to the second component.

In a preferred embodiment, a building material is provided comprising a lightweight cement-containing low cost core having a first side and a second side. The preformed fiber cement surface material is provided on at least the first side of the core. The fiber cement surface material is reinforced with individualized fibers having a substantially planar orientation. The core and the surface material simultaneously harden to form the building material.

In another aspect of the invention, a method of making a building material is provided. The fiber cement component of the predetermined size and shape is preformed such that the fiber cement component is uncured while firing. A second component made of the curable material adjacent to the fiber cement component is molded. At least the fiber cement component is cured to form the building material while the fiber cement component is adjacent to the second component.

In a preferred embodiment, the fiber cement component is a fiber cement sheath and the second component is a lightweight cementitious core having a first side and a second side. The fiber cement sheath is located adjacent to the first face of the cementic core. Fiber cement sheaths and lightweight cementitious cores are cured simultaneously to form building materials.

1 shows a cross section of a three layer sandwich composite material comprising two surface layers or a sheath and a solid core.

FIG. 2 shows an enlarged view of a three layer sandwich composite material comprising two surface layers or shell and solid cores.

3A-3C show three examples of many structural configurations that can be used in open core composite materials. The vertical (open pore cell is perpendicular to the shell) honeycomb core structure is shown in FIG. 3A. A vertical structure consisting of symmetrically facing corrugated core layers is shown in FIG. 3B. 3C shows a single corrugated core layer horizontal (open pore cell parallel to the shell).

4 shows a sandwich panel with a solid core. The first surface material 10 covers one surface and both sides and overlaps both edges of the opposing surface.

5 shows a plank with a solid core and a first surface material surrounding the surface and sides.

6 shows a trim board with a solid core and a first surface material surrounding the surface and sides.

7A-7G illustrate cross-sectional views of additional composite material products that may be prepared in accordance with preferred embodiments.

1. Composite Material Structure and Composition

A preferred embodiment of the composite building material is shown in FIG. The composite material preferably consists of a light weight core 12a, a fiber cement outer layer, shell or surface material 10, a second outer layer, skin or surface material 14. As used herein, the term skin, surface material or outer layer is used interchangeably. The use of the surface material and the core to form the composite material is only one embodiment of the present invention, and thus other building materials may be provided that are not limited to cores having surface material on one or both sides, including the concepts described herein. have.                 

In one embodiment the lightweight core consists of hydraulic cementitious binders, fillers, fibers and foams, and / or lightweight additives, as further described below. In one embodiment the fiber cement surface material 10 consists of hydraulic cementitious binders, fillers, fibers and additives. In one embodiment the second surface material is selected from the group consisting of thin fiber cement, fibrous mats, paper and polymer coatings.

1 through 3C illustrate a composite building material comprising three main layers as follows through a cross section of the composite material perpendicular to the principal plane axis of the composite material:

A first layer 10 of fiber cement on at least one surface of the building composite material,

Intermediate layers 12a-12d of the core material,

A second layer 14 of fiber cement or alternating surface material on opposite or remaining surfaces of the composite material not facing the first layer of fiber cement.

These embodiments may also have sublayers in or between major layers to provide improved interfacial bonding to the composite material or to provide other special functions. This sublayer or intermediate layer may also contain a reinforcing material embedded in that layer and the reinforcing material refers to the material described herein as the second outer layer.

It should be noted that the surface material may be applied to the surface or side of the core and is not limited to the large major surface of the composite material. 5 and 6 show, for example, planks and trim boards with a fiber cement surface material 10 applied over substantially the entire circumference of the core used for the planks and trim boards, respectively.                 

a. Material of fiber cement outer layer, sheath or surface material

In one embodiment the fiber cement sheath blend preferably comprises the following ingredients:

Hydroponic binder, preferably present at a concentration of about 10-80% by weight, more preferably about 20-50% by weight, most preferably about 25-40% by weight;

Filler present at a concentration of preferably about 0-80%, more preferably about 40-70%, most preferably about 45-65%;

Fibers present preferably at a concentration of about 1-25% by weight, more preferably about 2-16% by weight, most preferably about 5-12% by weight; And

Preferably at a concentration of about 0-20% by weight, more preferably about 0-10% by weight and most preferably about 0-6% by weight.

The hydraulic binder used in the fiber cement is preferably portland cement, but is not limited to hydraulic cementitious selected from the group consisting of high alumina cement, ground blast furnace slag cement, gypsum hemihydrate, gypsum dihydrate and hard gypsum or any mixture thereof. It may also be a binder.

Fillers which may be reactive or inert materials are preferably ground silica sand, including but not limited to amorphous silica, diatomaceous earth, rice hull ash, silica fume, microsilica, hollow ceramic spheres, geothermal silica, blast furnace slag, particulate slag, steel slag, May be any material selected from the group consisting of coal ash, inorganic oxides, inorganic hydroxides, clays, magnesite or dolomite, metal oxides and hydroxides, polymer beads or any mixture thereof.

Fiber cement additives include, but are not limited to, silica fume, hollow ceramic spheres, ceno spares, geothermal silica, flame retardants, curing accelerators, curing retardants, thickeners, pigments, colorants, plasticizers, dispersants, foaming agents, flocculants, water repellents, organic density modifiers, aluminum Powders, kaolin, alumina trihydrate, mica, metakaolin, calcium carbonate, wollastonite, inorganic oxides, inorganic hydroxides, clays, magnesite or dolomite, metal oxides and hydroxides, pumice, s Korea, tuff, shale, slate, perlite, vermiculite, polymer Bead, calcium silicate hydrate and polymer resin emulsion or any mixture thereof. Preferred polymeric resins are, but are not limited to, products such as acrylic latex, styrene-butadiene latex or mixtures thereof. These latexes can be in the form of emulsions or redispersible powders. In Portland cement based materials, the latex needs to be stabilized to withstand high alkaline environments.

The fibers used in the fiber cement are preferably cellulose wood pulp and include, but are not limited to, ceramic fibers, glass fibers, glass ceramic fibers, natural fibers such as kenaf, hemp, flax and jute, carbon fibers, mineral wool, In the group consisting of steel fibers, synthetic polymer fibers such as polyamide, polyester, polypropylene, polymethylpentene, polyacrylonitrile, polyacrylamide, viscose, nylon, PVC, PVA and rayon or any mixture thereof It may also be a selected natural or synthetic organic or inorganic fibrous material.

When cellulosic fibers are used, they are preferably unrefined / unfibrillated or refined / fibrillated cellulose from sources including, but not limited to, bleached, unbleached, semi-bleached cellulose pulp It is pulp. Cellulose pulp may be made from softwood, hardwood, agricultural raw materials, recycled waste paper or any other type of lignocellulosic material. Cellulose fibers can be produced by various pulping methods. In the pulping method, wood or other lignocellulosic raw materials, such as kenaf, straw and bamboo, can be transformed into fibrous materials by breaking the bonds in the structure of the lignocellulosic material. This can be done chemically, mechanically, thermally, biologically or by a combination of these treatments.

Cellulose fibers used to reinforce cement composites are mainly individualized fibers that partially or completely remove lignin components from the fiber cell walls. In one embodiment, at least 90% of the lignin component is removed from the fiber cell wall. This fiber is preferably produced by a chemical pulping method that separates the fiber depending mainly on the effect of the chemical. Based on the chemicals used in this method, the chemical pulping methods are Soda, Kraft, Kraft-AQ, Soda-AQ, Oxygen Deligninization, Kraft-Oxygen, Organic Solvent Method, Sulfur As a pump pump, steam explosion pulping or any other pulping technique. In the chemical pulping method, lignin, which acts as an adhesive to hold cellulose and hemicellulose together to provide the mechanical strength of wood, is destroyed and dissolved by chemical reactions.

These chemical reactions generally take place for about 30 minutes to 2 hours at a high temperature of 150 to 250 ° C. in a reactor called a cooker. The breakdown of the bond between the lignin and the cellulose component causes a weakening of the bond between the fibers. Under the action of weak mechanical force, cellulose fibers are separated into individual fibers. To date, the most common method for individualized fibers used in fiber cement composites is the kraft method.

The fibers are more preferably fibrillated cellulose fibers as described, for example, in Australian patent AU 515151. Fibrillation of the fibers involves first dispersing the fibers in water. This is preferably carried out in a vertical pulper (hydrapu1per) of the kind commonly used in the paper industry. Disc-shaped cellulose refiners are preferably used to rub, tear or rub the fibers to produce short hairy fibrils or tendrils from fine fiber strands. This process significantly increases the exposed surface area available for bonding when incorporated into the cementitious matrix. This fiber form allows for improved fiber-matrix bonding, resulting in improved strength and improved impact resistance and abuse resistance. This improved, more efficient reinforcement per unit volume of added fiber reduces the volume addition of the fiber needed to achieve the desired level of performance. This reduction in the required fiber content can significantly reduce the cost of raw materials, since the cost of cellulose fibers is substantially higher than other fiber cement components.

In one embodiment, the fibers are dispersed at a consistency of about 1% to 6% in a vertical pulper that also imparts some fibrillation. Further fibrillation can be accomplished using one refiner or a series of refiners. Once dispersed, the fibers are fibrillated in the range of about 100 to 750 degrees CSF (Canadian Standard Freeness), more preferably about 100 to 650 degrees CSF, even more preferably about 180 to 650 degrees CSF. do. Dispersion and fibrillation may also be carried out by other techniques such as hammer-milling, stripping, refining, sedan and the like. In addition, the use of unfibrillated fibers is also suitable for some products and methods. In another embodiment, processing also includes instantaneous drying of the fibers at a water content of about 5% to 50% using conventional instantaneous drying systems.

The orientation of the fibers in the surface material layer of the fiber cement is preferably parallel to the planar layer of the material, which increases the tensile strength of the shell by 10-20% compared to the irregularly oriented fibers in the fiber reinforced cement and concrete surface material. . More preferably, the fibers are oriented substantially in the load direction. It will be appreciated that the fibers may also be aligned in other respects to correspond to the desired load direction. The use of planar oriented fibers is more economical. This is because fibers are more expensive than inorganic matrix materials. The fewer fibers needed to obtain the desired strength and product, the more durable the matrix components are less lean by the fibers, resulting in greater durability. Again, as noted above, preferred fibers for the fiber cement surface material are dispersed and fibrillated cellulose fibers prior to the preparation of the surface material. Such separated or individualized fibers have a larger surface area available for bonding to cementitious materials due to the fibrillation process. Higher binding per unit volume of fiber cement leads to greater strength and improved durability.                 

The separated or individualized fibers are mixed proportionally with other components to form a mixture which may be an aqueous slurry or a semi-dry paste, depending on the manufacturing method to be used. In one embodiment, the cellulose fibers are mixed with cement, silica, density modifiers and other additives by known mixing methods to form a slurry or paste. In the mixer, normal cellulose fibers and / or natural inorganic fibers, and / or synthetic fibers may be blended with the engineering fibers.

The fiber cement surface material may be molded from the firing mixture or the aqueous slurry into shaped articles by post-compression or without post-compression by many conventional methods, such as:

Hatschek sheet process;

Mazza pipe process;

Magnini method;

Injection molding;

Extrusion;

Hand lay-up;

Molding;

· casting;

Filtration compression;

· Fooddrinier molding;

Multi-wire molding;                 

Gap blade molding;

Gap roll / blade molding;

Bel-Roll molding;

Wellcrete;

· Other.

These methods may also include post-molding methods, such as compression, embossing, and the like, after the article is molded but before it is cured. The processing steps and parameters used to produce the final product using the Hunk method are similar to those described in Australian Patent No. 515151. Thus, the product formed after the processing described above is in a sintered state that allows its shape to be shaped and shaped but not yet cured. As described below, the curing of the product preferably takes place simultaneously with the core material.

b. Core structure and material

The core structure may be a solid core (element 12a in FIGS. 1 and 2) or an open core (elements 12b, 12c and 12d in FIGS. 3A, 3B and 3C, respectively). Alternatively, the core may be considered homogeneous or heterogeneous (ie, the core is itself a composite material). Composite density can be reduced using one or a combination of the following methods:

Absorbing large volumes of bubbles, preferably having a bubble size of about 0.02-1 mm, into the core slurry (solid core structure),

Adding a large volume of low density material to the core slurry (solid core structure), or

Forming the core together with the structural reinforcing material to form an open network having a large porosity (structural porosity, typically having a pore dimension of at least about 10% to 90% of the core thickness) but with a structural design exhibiting adequate core strength (Open core structure).

Large volumes of bubbles can be introduced into the core by adding the blowing agent directly to the slurry and foaming in situ, or preferably by adding bubbles generated from the bubble generator. The pores are also formed by adding a reactive gas forming metal powder to an alkaline cementitious slurry, such as aluminum powder, to generate gas voids. Low density additives are added directly to the slurry and do not require further processing. Fabrication of the open core structure involves fabrication of the core prior to assembly of the composite material.

In the case of an open structure core design, the core is preferably made of a strong material of a shape and orientation that structurally reinforces and supports the surface material. The purpose is to form the strength and stability of the integral sandwich composite material using an open structure design that includes a large volume of space to reduce the weight of the composite material. Such structural designs include open honeycomb and corrugation. The axis of the reinforcing core structure can be oriented parallel or perpendicular to the planar axis of the composite material. Structural reinforcement materials are made of fiber cement of the methods and compositions described above or other cost-effective rigid materials, such as plastics, fiber reinforced plastics, metals or cardboard materials (preferably wall thickness of ≤ 1/4 inch) Can be. A preferred method of producing open structure core designs such as honeycomb or other multi-bubble structures is by extrusion. Another preferred embodiment is coextrusion of the core and surface material.

In one embodiment the solid core blend comprises the following ingredients:

Binder present at a concentration of preferably about 10-100% by weight, more preferably about 20-50% by weight, most preferably about 25-40% by weight;

Preferably in a size range of about 0.02-1.0 mm, preferably present at a concentration of about 0-80% by volume, more preferably about 20-70% by volume and most preferably about 25-50% by volume. Pores formed by foaming the slurry;

Filler present at a concentration of preferably about 0-80%, more preferably about 40-70%, most preferably about 45-65%;

Fibers present preferably at a concentration of about 0-5% by weight, more preferably about 0.25-2.0% by weight, most preferably about 0.5-1.0% by weight; And

Additives and admixtures which are preferably present at a concentration of about 0-20% by weight, more preferably about 0-10% by weight, most preferably about 0-6% by weight.

The solid core composition preferably comprises the foams, fillers, additives and admixtures necessary for the core properties and can be bonded together by an organic (polymer) or inorganic binder. The polymeric binder may be foamed or unfoamed and may contain fillers. Preferred binders for use in these materials may be, but are not limited to, inorganic hydraulic binders selected from the group consisting of portland cement, high alumina cement, ground blast furnace slag cement, gypsum hemihydrate, gypsum dihydrate, pumice gypsum or any mixture thereof. have. More preferably, the binder is Portland cement, gypsum hemihydrate, gypsum dihydrate, pumice gypsum or any mixture thereof.

Admixtures for solid core slurries include viscosity modifiers, accelerators, retarders, blowing agents and dispersants. Light weight aggregates or fillers are used in addition to or instead of blowing agents to reduce core density. Light weight fillers include expanded minerals such as perlite, vermiculite, shale and clay, expanded polystyrene spheres and coal ash. Moisture resistant additives used individually or in combination with these cores include emulsions of wax and / or asphalt, polyvinyl alcohol, siloxane emulsions, metallic soaps and stearates. Films or resinous coatings formed by materials such as styrene-acrylic latexes can be used to further improve moisture resistance and surface quality. Additives used to improve fire resistance include gypsum, mineral fibers such as glass and wollastonite, mineral additives such as unfoamed vermiculite, mica, hydrated alumina, bauxite, clay and mixtures thereof.

Other materials that can be used for the core include those described for the surface material, as described in the paragraph entitled, "Overview of Other Sandwich Composite Material Embodiments".

c. Material of the second outer layer, skin or surface material

If used, the second layer or sheath may be supplied in a generally planar form such as continuous fibrous or fiber reinforced composite sheet, mat, plate, film or coating, and may be metal, plastic, wood, paper, organic or inorganic fibers. , Cementic or non-cemental binders, fillers, additives or mixtures thereof. Preferred non-cementable binders include, but are not limited to, polymers such as acrylic and styrene-butadiene latex. In one embodiment, the second surface material is a fiber cement made similar to the first surface material described above. In another embodiment, the second surface material is made of a different material from the first surface material. Preferred materials to be used for the second sheath include thin fiber cement, fibrous mats, paper, continuous strand two dimensional mats, and polymer coatings. Preferred fibrous mats are made of glass fibers and can be nonwovens (veils) or wovens (screams) using continuous or cut fibers. The glass fibers are preferably alkali resistant or polymer coated. The surface of the second layer can be shaped, embossed or patterned for aesthetics or functionality if desired. Other examples that can be used for the second surface material are described in the paragraphs below under the heading "Summary of Other Sandwich Composite Material Embodiments".

d. Composite material processing

After the preparation of the above components, the composite material is preferably sufficiently cured to obtain minimal stiffness before further processing. If minimal strength is not maintained, physical manipulations required for handling, cutting, and hitting processes can cause damage such as cracking in the core or delamination at the core-shell interface. Depending on the formulation, the composite material may be air cured, high temperature cured, steam cured, carbonized or precured and then autoclaved, or cured by a combination method thereof. The length of time needed to strengthen the composite and the temperature-time schedule required for proper curing will depend on the formulation, the preparation method, and the size and shape of the composite material. These factors can be adjusted by setting-controlling admixtures and / or adjusting process parameters such as temperature. It will be appreciated that the curing described herein includes the set of curing over time of non-cemental materials (eg, polymers) as well as cementitious materials.

In one embodiment, the uncured fiber cement surface material is preferably preformed by slurry dehydration methods such as the hatch method to form a sheet that is moldable but uncured prior to the manufacture of the composite material as described above. The composite building material is preferably assembled in an uncured state and then cured. In one embodiment the composite material may preferably be precured first in a precure chamber of high temperature and relative humidity or in a precure chamber of high temperature and low humidity. Or preferably, precure is carried out at ambient temperature for up to 80 hours, most preferably up to 24 hours. Thereafter, the article may be air cured for about 30 days in one embodiment. More preferably, the precured product is autoclaved at about 60 to 200 ° C. for about 3 to 30 hours, more preferably up to about 24 hours at high temperature and pressure under a steam saturated environment. The time and temperature chosen for the preliminary curing and curing process depend on the formulation, the preparation method, the process parameters and the final form of the product.

Although the embodiment described the simultaneous curing of the fiber cement surface material and the core, it will be appreciated that the curing does not have to be done simultaneously. In other embodiments, the curing may be done in parallel or sequentially when the core and fiber cement are cured at different times. The core may also be made of a material that does not require curing. In these embodiments, only the fiber cement component is cured. It will be appreciated that the fiber cement may be partially cured or dried prior to molding the composite building material.

The manufacture of the composite material is done by uncured fiber cement sheets to form stronger interfacial layer bonds to withstand or essentially eliminate core-shell interlayer separation during handling, cutting, installation and service. Co-hardening of the core and sheath forms an interpenetrating mechanical and chemical bond between the core and the fiber cement sheath. This type of bonding is stronger and more durable than forming composite materials using hardened fiber cement sheaths and does not require adhesive to bond the layers together. Promoted hydroponic binders preferably enhance continuous processing speed and allow for more processing. The use of fiber cement surface material provides excellent moisture and abuse resistance of the composite material. Good fire resistance can be obtained by the use of additives which effectively delay flame heat conduction and control the permeability of the microstructure. The composite material may also be designed to have an interlayer of organic or inorganic materials or mixtures thereof, for example, to provide special functionality by improving core-shell bonding, moisture control, insulation and fire protection.

The use of accelerators results in the rapid reinforcement required for high speed continuous production of the composite material. Permeation of the accelerator in the core slurry into the uncured surface material during manufacture may promote curing of the fiber cement surface material. Fast production rates require rapid reinforcement of the composite material for cutting and hit handling without collapsing the core or damaging the composite material.

The use of preformed uncured fiber cement sheaths provides many advantages outlined as follows: First, improved sheath-core bonds resulting from interpenetrating mechanical and chemical bonds. This type of bond is stronger and more durable than the mechanical bonds that occurred primarily between the hardened fiber cement and the core of the prior art, so this improved bond exhibits higher flexural strength. In addition, improved bonding will improve the resistance or potential for elimination of core-shell interlayer separation that may occur during handling, cutting, installation and service.

The use of preformed uncured fiber cement sheaths also shortens manufacturing time. Uncured sheaths may be made and molded, stamped or embossed simultaneously prior to assembly of the composite material. The uncured bottom sheath can act as a carrier sheet and also by bending the soft sheath material upwards at the edges, it acts as a mold for the core material allowing for the continuous production of the composite material.

The method and formulation also improve the skin-core interlayer formation. Admixtures, such as antifoams in the uncured fiber cement sheath, cause bubble breakage of the foam structure at the sheath-core interface, forming a dense interlayer with higher contact surface area, thus forming stronger bonds of the core to the sheath. It is also possible to control the thickness of the dense interlayer formed by carefully controlling the water content in the uncured sheath. The drier sheath absorbs more water from the core slurry and causes more bubble breakage of the foam structure at the sheath-core interface, resulting in a denser and thicker intermediate layer. The dense interlayer material may be applied to the core side of the fiber cement sheath prior to assembly to further improve core-shell bonds.                 

Improved skin hardening and skin properties are also formed from the embodiments described above. Admixtures such as accelerators in the core slurry can be sucked into the fiber cement capillary network to promote curing of the fiber cement sheath. The cementitious material in the core slurry can be sucked into the fiber cement sheath duct network to substantially reduce the permeability of the fiber cement material by filling the capillary with the cementitious reaction product. This method has unexpectedly surprising results in reducing fiber cement permeability by 95%.

e. Different types of composite building materials

While the sandwich type composite materials described herein represent only one embodiment of the present invention, it will be appreciated that other types of composite building materials may be made, including preformed uncured fiber cement components.

7A illustrates one embodiment of building material having a circular cross section in which lightweight material 16 as described above surrounds fiber cement component 18 as described above. As shown in FIG. 7A, the fiber cement component 18 may be solid, or as shown in FIGS. 7B and 7C, the fiber cement component 18 may be annular. In FIG. 7B, a lightweight core 20, which may be the same or different material as the outer layer component 16, is provided in the fiber cement component 18. In FIG. 7C, this core 20 may be annular to form a hollow region of building material therein.

It will be appreciated that in FIGS. 7A-7C components 16 and 18 can be changed such that the fiber cement component surrounds the lightweight core. Also, as shown in FIGS. 7D-7F, many other types of building materials may be assumed that are not circular. 7D-7F illustrate one embodiment in which a rectangular core 24 of lightweight material is surrounded by fiber cement surface material 22 in all directions around it. This surface material 22 may only partially surround the core without enclosing all directions around the core 24.

In Figures 7E and 7F, another embodiment in which the core 26 is surrounded by two surface layers 22 and 24, one of which may be fiber cement and the other may be the same or different material, as described above. Is illustrated. In FIG. 7F it is illustrated that the core 26 may be hollow.

7G illustrates another embodiment in which the lightweight core 30 is sandwiched between two surface layers 28 and 34, which may be fiber cement surface materials as described above. Core 30 may be a composite material that is self-reinforced with exemplary reinforcement 32, which may be a fiber or other material.

2. Examples of Preferred Fiber Cement Jacketed Building Materials

One preferred embodiment of the present invention is a lightweight, cement-containing low cost at least partially enclosed by a fiber cement sheath having a thickness of less than about 3/16 "having high durability to exposure to sunlight, water and atmospheric gases when cured. Including building materials made from the core The bond between the fiber cement sheath and the lightweight core is cementitious The thin, uncured fiber cement sheath can be bent, overlapping or contoured. The core surface portion, which is not present, can be left unsurfaced or surface finished with another sheet material described herein as the second outer layer, if desired.

The composite material preferably has one or more of the following improved properties, including less cost, durability and processability (handling, shape cutting and fixing). In addition, by using the sandwich composite material as described above, a multifunctional performance obtained by combining strength, abuse resistance, fire resistance, low acoustic propagation and aesthetics can be obtained. In terms of ease of manufacture, the use of thin raw sheets allows the shell to form a moldable mold for the core. The additive may allow the core and skin to cure quickly and controllably to form a cementically bonded unitary.

The use of preformed uncured fiber cement sheaths in the production of sandwich composite boards is much more efficient than using hardened fiber cement sheaths. The use of hardened fiber cement sheaths requires the use of molds containing flowable core slurries or the use of non-flowable core blends to be compressed to obtain planar contours. Both of these methods will significantly slow down the production rate.

The plasticity properties of the thin, preformed raw fiber cement sheath of the preferred embodiment also allows the sheath to wrap around the corners to form a right angled or contoured shape that is not possible by the hardened fiber cement sheath.

The multifunctional performance of these embodiments has the desired properties of fiber cement, such as:

Non-flammable,

Low flame spread,

Anti-corruption,                 

Mildew and bacteria resistance,

Insect repellent,

Finished exterior paint

External durability,

Moisture decomposition resistance,

Weather resistance,

Abuse resistance

And additional functional properties derived from the composite design and the synergistic combination of materials, such as:

Shear strength of frame walls, similar to plywood and OSB covers,

Fire resistance of framework walls similar to X-type gypsum wallboard,

Thermal insulation similar to foamed plastics,

Structural suitability for partition walls similar to engineered wood panels.

Acoustic absorption or low acoustic propagation,

The formability of the composite material, which forms overlapping corners, architectural contours or makes the entire shell of fiber cement around the core material due to the plastic state of the fiber cement sheath

Is obtained by combining

Examples of preferred multifunctional embodiments or products are described below.

a. Refractory + Cladding or Support

An example of a preferred product combines the desired properties of the refractory core material and fiber cement so that the composite material achieves a fire rating equivalent to that of the X-type gypsum wallboard when tested in accordance with ASTM E 119 for the inner and outer wall and ceiling assemblies. The advantage of this material is that it provides both fireproof and durable exterior in a single product. Traditional systems require multiple building products to achieve equivalent functionality, such as a combination of X-shaped gypsum wallboard and exterior cladding.

b. Insulation + Cladding or Support

Another example of a preferred product combines the desired properties of the insulating core material and the fiber cement to obtain higher R-values when tested according to ASTM C-177. The advantage of this material is that it provides both a thermally insulating and durable outer surface to the structure. Traditional systems require a combination of building products to achieve equivalent functionality, such as a combination of foamed plastic insulation panels and exterior cladding.

c. Refractory + Insulation + Cladding or Support

Another example of a preferred product is that of the desired insulation core material and fiber cement in order to obtain a higher R-value when tested according to ASTM C-177 and also to obtain a fire rating equivalent to 5/8 "thick X-type gypsum wallboard. The advantage of this composite is that it provides the building assembly with fireproofing, insulation and a durable exterior The traditional system achieves the same functionality as the combination of X-type gypsum wallboard, foamed plastic insulation panels and exterior cladding. In order to need multiple building products.

d. Shear strength + cladding or support

Another example of a preferred product combines the racking shear strength and the desired properties of the fiber cement, tested according to ASTM E 72, provided by fixing the composite material to the skeletal assembly. The advantage of this material is that it provides the shear strength required for assemblies having a durable outer surface (when tested for ASTM E 84) that are non-flammable and have low surface combustion properties. Traditional systems such as APA grade sheaths and siding are combustible and have higher surface combustion characteristics.

e. Shear strength + fireproof material + cladding or support

Another example of a preferred product combines the desired properties of a fire resistant core and fiber cement to achieve a fire rating equivalent to that of an X-type gypsum wallboard with adequate racking shear strength. The advantage of this material is that it provides shear strength, fire resistance and a durable exterior to a single building product. Traditional systems require multiple building products to achieve equivalent functionality, such as a combination of X-shaped gypsum wallboard and APA grade cover or siding.

f. Shape formability for cladding or trim or decorative plates

Another example of a preferred product combines the formability of a thin, preformed fiber cement raw sheet with the desired properties of the fiber cement to form the architecturally desired shape. The advantage of this material is that it provides a contoured or shaped building product without the need for post hardening machining. Traditional contoured fiber cements are expensive due to machining and tooling costs and the costs associated with the control and disposal of dust generated from machining. Thicker, lighter, more complex forms than conventional fiber cement can be made from these composite materials.

3. Outline of Other Sandwich Composite Material Embodiments

Although the preferred embodiments have been described, this section further describes sandwich composite materials, including those encompassed by the preferred embodiments, in comparison to other types of sandwich composite materials traditionally known.

In general, a high strength to weight ratio can be obtained by using a sandwich composite design that combines a lightweight rigid core with a high tensile strength sheath. Products using this type of design include aircraft wings, surfboards, boat hulls, cooling panel panels and hollow doors. Sandwich composite building panels include gypsum wallboard with paper surface finish and fiberglass mat surface finish, fiberglass scrim reinforced cementitious tile supports and covers, and gypsum support plate with fiberglass mat surface finish.

a. Common building materials

Some of the common building materials have multilayer structures such as plywood and fiber cement sheets. The composition and structure of each layer in this particular multilayered material is mainly the same. Most fibrous reinforcements are oriented or directional in each layer, so that the physical properties of the composite material will be oriented. For example, the tensile degree of the composite material is greater in the plane (layer) direction of the material than in the direction perpendicular to the layer. The layers can be positioned such that the composite material is aligned in the direction in which all the layers are oriented, such as fiber cement, or the alternating layers are aligned at right angles, such as plywood. The orthogonal alignment of adjacent oriented layers greatly reduces the directionality in the composite material properties.                 

Sandwich composites generally contain at least three major layers and typically consist of a shell or surface material covering a relatively light weight core. The surface material of the sandwich composite material is generally chosen to give strength to the composite material. External durability and moisture resistance are often not inherent in high strength skins. Fiber cement sheaths provide the moisture resistance and durability required for exterior building products such as siding, wall panels, trim, soffit, shingle and roof tiles. High strength and rare composite materials are needed to facilitate the installation of building products. This allows the large sheet to be handled without excessive physical force and without sheet bending fracture. The total weight of the composite material is reduced by adding foam and / or lightweight filler to the core blend of the sandwich composite material.

b. Sandwich Composite Design

Sandwich composite structures using a lightweight core and relatively high tensile strength sheath or surface material allow the composite material to be made thick enough to impart structural stiffness without being too heavy to handle. The flexural strength of the composite material is mainly determined by the tensile strength of the sheath if the strength of the bonded interface between the sheath and the core is appropriate. Failure due to bending of the sandwich composite can occur in three different directions. The surface may break upon tension, and upon compression the surface may be buckled and / or separated from the core, or the core may break under shear load. Breaking under shear load can occur near the interface of the core and shell or within the core itself. Good interfacial bonding between the core and the sheath is typically required when using lightweight core materials with high porosity.

c. Surface material of sandwich composite building material

The surface material or sheath is generally in the form of a planar material consisting of sheets, mats, plates, films and coatings. Such surface materials may be made of materials such as metals, plastics, wood, paper, organic or inorganic fibers, and cementitious materials. Surface materials used in sandwich composite building materials as described herein include paper sheets, fibrous mats, fiber reinforced cement (FC) and fiber-matte reinforced cement (FMC).

(1) Performance of surface material in wet environment

The wet and dry strengths of typical gypsum papers are shown in Table 1 below in comparison to cellulose fiber cement prepared by the Hunk method. When dried, the strength of gypsum paper was nearly several times that of fiber cement. However, when the surface material was saturated with water, the strength of the gypsum paper was less than 3% of its original strength, while the fiber cement maintained about two thirds of its dry strength.

The tensile strength  Surface material Drying (MPa) Wetting (MPa)  Gypsum Paper (0.014 "Thickness) 40 One  Fiber Cement (0.068 "Thickness) 6 4

Paper used as a surface material is very strong when dried, but loses almost all of its strength when exposed to a wet environment. Adding water repellents to paper improves water resistance, but prolonged exposure to moisture can still reduce core-paper bond strength and paper tensile strength. This ultimately leads to delamination of the paper from the core and / or destruction of the core material under minimal bending, shear or tensile load.

(2) surface abuse resistance of surface material

Building materials such as wallboard are subject to human traffic, and the surface of the building material is therefore desired to be abuse resistant. Fiber cement has much better surface abuse resistance than that of conventional paper surface finished building materials such as gypsum wallboard. One measure of abuse resistance is the resistance of the surface to wear or loss of material from abrasion caused by a human or device collision with the wall surface. Surface wear resistance of fiber cement and gypsum wallboard was measured using the ASTM D4977 test method, which was modified using a 25 lb load on a steel brush. The wear depth measured after 50 cycles was found to be 1.75 mm for gypsum wallboard and <0.01 mm for fiber cement wallboard.

(3) Flame and fire spread of surface material

Another concern when designing and selecting building materials is the resistance of the material surface to the promotion of fire spread in buildings and the fuel supply to the fire. Surface fire resistance of paper surface finished building products is poor compared to cement based or inorganic materials due to the flammability of wood fibers in paper surface materials.

(4) fibrous mat surface material

When fibrous mats are used in wallboards, covers and support plates, they are generally made of uncoated or coated glass fibers. The fibrous mat may be a nonwoven (veil) or a woven (scream) and consists of chopped or continuous fibers. Scrims are generally more expensive than bales, but are typically stronger and more durable. Fibrous mats are more durable than paper surface materials. Paper surface materials are generally stronger when dried, but fibrous mats have a much higher wet strength. ASTM C1154-99 defines fibrous mat reinforced products (FMC) as "manufactured flake composite materials of non-asbestos fibers and hydraulic cementitious matrices of two-dimensional scrim".

(a) nonwoven fiberglass mat surface material

Fiberglass mats have been used to improve the moisture and fire resistance of gypsum board products. However, the composite material is still prone to deterioration after prolonged exposure to moisture due to the water solubility of the gypsum. This can gradually reduce the strength of the core and mat-core interfaces. Another concern with the fiberglass mat surface material is skin irritation resulting from the handling of the composite material. The glass fibers contained in the mat are typically less than 0.001 inches in diameter and can therefore be broken and buried in the skin that comes into contact with the mat during handling. This buried fiberglass fragment causes skin irritation. Polymeric coatings further require improved water resistance of both paper and fiberglass surface materials. Such coatings generally slow down the rate of water penetration into the core material.

(b) fiberglass scrim

Fiberglass scrims are used to reinforce plate products such as Portland cement based ceramic tile support plates. However, the durability of fiberglass scrims made from A-glass (soda-lime-silica) or E-glass (borosilicate) is generally greatly reduced when used in materials and construction systems containing portland cement. Fiberglass breaks down in the high alkaline environment of Portland cement and loses strength. Although the actual mechanism is not well understood, destruction commences with the formation of alkali silicate gels. Glass fibers are relatively reactive due to their large specific surface (small diameter and high aspect ratio) and quickly lose their strength when the structural material is lost to gel formation. To overcome this, glass fibers must be coated with a polymeric material, such as polyvinyl chloride, to withstand the degradation of the composite material in a wet environment. Another solution is to use fiberglass scrims made of alkali resistant (AR) fibers. These fibers consist of soda-lime-silica glass containing at least 16% by weight of zirconia. The addition of zirconia significantly increases the cost of glass fibers. Thus, using coated fiberglass scrims is less expensive than using alkali resistant fiberglass scrims. Another concern with the use of fiberglass scrim is that the surface of the plate will not be smooth unless the plate is completely buried in the core or a suitable surface coating is applied.

(5) fiber cement surface material

ASTM C1154-99 defines fiber cement (FC) products as "manufactured flake composite materials of hydraulic cementitious matrix and separated non-asbestos fibers". Fibrous mat reinforced cement products (FMC) are defined in ASTM C1154-99 as "manufactured flake composite materials of two-dimensional scrim's non-asbestos fibers and hydraulic cementitious matrices".

Portland Cement Based Fiber Cement (FC) and Fibrous Matte Reinforced Cement (FMC) Surfaces include Wall Panels (King, U.S. Pat. And composite materials developed for such applications as various structural materials. Two general types of such surface materials are used: 1) manufactured (prefabricated) prior to assembly of the composite material and 2) formed in situ from the uncured material as part of the sequentially layered composite material. that. In a preferred embodiment, the production of sandwich composites using a continuous, preformed uncured fiber cement surface material as described above has not been found in the prior art.

(a) prefabricated hardened fiber cement surface material

Prefabricated hardened fiber cement surface material is used to form cast and molded composite materials larger than 1-½ "thick. Such as structural walls, panels, beams, girders and joists Cast-in-place composites use prefabricated cured sheets as the rigid skeleton in which the core is cast (Jones, Jr., US Pat. No. 5,473,849) .The composite material is installed on a supporting wall frame like most wall plates or wall coverings It is not designed to be, but instead is designed to span from floor to ceiling, such as a partition wall composite panel .. The method of forming such composites is provided between the formwork sheets, except that the fiber cement surface material (similar to formwork) is permanent in this case. Similar to pouring concrete, the technology of forming such composites is thick enough to handle without damaging the panel and during casting of the core There is a need for a fiber cement sheath that is strong enough to withstand the hydrostatic pressure generated from the core blend. The fiber cement surface material has a thickness of ≧ 3/16 ”to provide sufficient strength for processing composite materials. It is also desirable that the bond between the surface material and the core is good, while the formwork must have a weak bond to the concrete so that it can be removed and reused. There is a similar method of using molds to mold building panel composites (Cottier, et al., Australian Patent No. 661,704). The core is cast on the cured fiber cement surface material sheet and then covered with the top fiber cement surface material sheet.

(b) Co-molded Fiber Cement Sandwich Composites

Three classifications used in ASTM C 1154-99 to describe other reinforced composite building products are cement bonded particle boards, fiber cement, and fibrous mat reinforced cement.

The uncured cement bonded particle board and the fibrous mat reinforced cement (FMC) surface material are field molded as part of the composite material fabricated from the sequentially deposited layers. The sheath and core are comolded in one way to make sandwich composites. The bottom surface material is first molded and then the core material, followed by the top surface material. These composite materials can be continuous molded integrally cut and trimmed to size, or can be molded individually to the desired size. The core and sheath material may be a slurry of another composition that is cast or sprayed or may be a particulate material that is compressed to solidify the composite material.

Examples of co-formed sandwich materials are described in US Pat. No. 5,693,409 to Gnatowski et al. This material is processed by sequential deposition of layers and describes fiber cement as the surface material layer. The description of the fiber cement used in the NATO whiskey patent differs from the fiber cement of the above preferred embodiment as described in ASTM C1154-99. The difference between the materials described as both fiber cements is that the fibers are separated and individualized fibers in certain preferred embodiments of the present invention and in ASTM C1154-99, while the reinforcing fibers in US Pat. No. 5,693,409 are wood fiber strands or wood chips. It is explained. Wood fiber strands are described as having a length greater than 10 mm. Wood fiber strands of this length are better described as wood flakes that include fibers that are naturally bound by lignin. Wood fiber strands or wood chips in the cementitious matrix are more typically described as cement bonded particle boards defined in ASTM C1154-99 as "a manufactured plate of hydroponic cementitious matrix and fibrous wood particles". The external durability of cement bonded particle boards is inherently poor due to the swelling of the wood fiber strands in the fragile cement matrix. This swelling leads to microcracks in the cement matrix, reducing the strength of the plate and increasing its permeability, thereby lowering its durability.

Another example of a method of making a co-molded three layer composite material is described in King, US Pat. No. 5,002,620. The two outer layers are formed of relatively dense, fiber reinforced concrete, and the core is made of lightweight fiber reinforced concrete. In this method, the core concrete density is modified by adding bubbles to the core material. The concrete core consists of Portland cement, suitable aggregates, fibrous reinforcement materials, ash from waste solid fuels, foam silicates, water, sand, suitable blowing agents, compressed gas sources, and suitable vapor barrier resins for bonding and moisture resistance. The layers are formed by sequentially casting into a mold from the hopper. Therefore, the fibrous material in the surface material layer is distributed in irregular orientation without the intentional orientation of the fibers in terms of the material parallel to the face of the layer. The composite material layer is made of concrete. Concrete generally has coarse and fine aggregates in the composition. Fine aggregates are sand and coarse aggregates remain primarily on the 4.75 mm (4) sieve as defined in ASTM C 125-96. In order to obtain good tensile strength in the surface material layer, the effective thickness of the surface material layer must be significantly larger than the coarse aggregate size.

d. Core material

The core may be made lightweight by incorporating a large volume of pores or lightweight material into the integral cementitious material, or by fabricating the core to have an open reinforcing framework that forms large pores. Most composite materials use the first method and the core contains a large volume of bubbles or a sufficient amount of low density fillers to produce a relatively lightweight composite material. The most common method of adding a large volume of pores to the core slurry is to mix it with bubbles generated using blowing agents. As a result, many pores are irregularly distributed. Foam concrete is a representative core material and is defined in ASTM C 125-96 as a lightweight hydraulic cement with homogeneous pore or bubble structure obtained using gas forming chemicals or blowing agents. The foams, fillers and admixtures necessary to achieve the desired core properties can be bonded together by organic (polymeric) or inorganic binders. The most common type of binder used in building materials is an inorganic hydraulic binder. The most common and economical inorganic hydraulic binders are gypsum and portland cement.                 

(1) structural open skeletal core

The second method of producing a lightweight core involves the use of an open reinforcement skeleton. The core is made of a material that is strong in shape and orientation to structurally reinforce and support the surface material. Its purpose is to achieve the strength and stability of the integral sandwich composite material using an open structure design that includes a large volume of space to reduce the composite material weight. Such structural designs include open honeycombs and valleys.

(2) core composition

Typical admixtures for cementitious core slurries include viscosity modifiers, accelerators, retarders, blowing agents, dispersants, and additives to improve moisture and fire resistance. Light weight aggregates or fillers are used in addition to or instead of blowing agents to reduce core density. Light weight fillers include expanded minerals such as perlite, vermiculite, shale and clay, expanded polystyrene spheres and coal ash. Moisture resistant additives used individually or in combination with these gypsum cores include emulsions of wax and / or asphalt, polyvinyl alcohol, siloxane emulsions and metallic soaps. Films or resinous coatings formed by materials such as styrene-acrylic latexes are used to further improve moisture resistance and surface quality. Additives used to improve fire resistance include gypsum, mineral fibers such as glass and wollastonite, mineral additives such as unfoamed vermiculite, mica, hydrated alumina, bauxite, clay and mixtures thereof.

4. Advantages of sandwich composites made from preformed uncured fiber cement surface material

One advantage of using the fiber cement surface material described herein is that it provides a smooth surface compared to glass fiber mat surface finished composite materials. In the case of facing materials, the smooth surface of the fiber cement provides a better surface for painting than wood products where shrinkage of wood near the wood leads to cracking of the coating. The raw fiber cement surface material may also be molded or secondary molded into the textured surface using flat plate press or roll-pressure processing to provide an architectural finish such as wood or cement texture to the product. The sandwich panel with scrim surface finish mainly functions as a support for other materials and does not provide a finished surface. The fiberglass mat surface finished composite material contains small diameter fiberglass that can cause skin irritation when the composite material is handled during delivery and installation. Paper surface finished gypsum wallboard often has a texture printed on the paper to act as a finished surface, but this surface texture has little depth and no external durability compared to fiber cement textures.

The surface porosity and surface texture of the unpatterned fiber cement is less noticeable than that of cement plate with fiberglass mat surface finish. The fiberglass mat surface material has an open fabric structure or open structure that provides little resistance to water penetration into the core material. Fiber cement surface material is a more continuous material, providing an excellent barrier against water penetration into the core material when compared to fiberglass mats and scrims. The water penetration of the fiber cement material into the surface is considerably smaller than that of glass fiber surface finished cement plates. A 4 ft hydraulic head against a fiber cement surface through a 2 "diameter tube allows only one tenth of the volume of water to penetrate the surface of the fiber cement plate compared to a fiberglass mat surface finished cement plate.                 

Fiber cement is non-flammable and has a very low flame spread, but does not have the same fire performance as gypsum wallboard in fire rated wall systems. Conventional steel partition walls or wooden walls alongside 5/8 "thick X-type gypsum wallboard on both sides of the framework are tested according to ASTM E 119, respectively Gypsum Association Fire Resistance Design Manual GA 1 hour fire resistance when installed in accordance with piles WP 1200 and WP 3520. A similar wall system with fiber cement on one side and a 5/8 "thick X-shaped gypsum wallboard on the other will achieve a 1 hour fire rating. In order to do this, the wall holes need to be insulated with mineral fibers. Therefore, this type of installation is more expensive and requires extra material and more time to install. Such insulated walls have the advantage of providing a fiber cement surface on one side of the wall that can be used on a side that is prone to abuse, or as a support for ceramic tiles. A preferred embodiment of the present invention describes an excellent product that provides a fiber cement building board composite material that can have the fire resistance performance of gypsum wallboard, and the abuse resistance, moisture resistance and durability of fiber cement.

In general, sandwich composite materials of the prior art using fiber cement sheaths on both sides of a lightweight core have been limited to use the thickness of the material that can be molded and handled with the composite material. The outer sheath is approximately 3/16 "thick and hardened to provide sufficient strength for molding and handling into composite materials. The product is molded to a thickness of 1-½" or larger and floor to ceiling as a full wall panel or partition wall. I was on. The preferred embodiment described above is an improvement over the prior art as it uses a thinner fiber cement sheath to form a sandwich composite material. This improvement is achieved without the handling problems of the prior art as the thin fiber cement sheath is formed of a sandwich composite material in the form of a fired and uncured raw sheet. The plasticity properties of the shell during composite material formation provide improved design flexibility that enables the shaping of flat surfaces, textures and contoured shapes of the composite material. Thin fiber cement sheaths also allow lighter, thinner composite materials to be produced that can be attached to full length wall frames representing gypsum wallboard and wall covering. By using a thinner sheath, more light weight cores are used with a constant sheet thickness, resulting in a lighter composite as a whole.

Thus, the fiber cement sandwich composite material of the preferred embodiment is easy to handle, nail and calibrate, and has a lightweight wallboard / cover composite material that has the strength, durability, moisture resistance and abuse resistance of the fiber cement together with the thermal and fire resistance of the gypsum. to provide.

It is to be understood that certain changes and modifications of the invention can be made by those skilled in the art. It is intended that the scope of the invention be limited not by this example or above description, but only by the appended claims.

Claims (55)

At least a first component and a second component adjacent to the first component, The first component is provided as a preformed uncured fiber cement with a fiber content of about 5-12% by weight, wherein the fibers of the first component extend in a planar orientation parallel to the surface of the preformed fiber cement layer, After the fiber cement is reinforced with individualized fibers, at least some of the components form an interpenetrating mechanical and chemical bond, the uncured fiber cement providing the first component adjacent to the second component. Building material to be cured. The building material of claim 1, wherein the second component is made of a curable material. The building material of claim 1, wherein the first component and the second component are cured simultaneously. The building material of claim 1, wherein the first component and the second component are cured sequentially. The building material of claim 1, wherein the first component is partially dried before providing the first component adjacent to the second component. The building material of claim 1, wherein the second component has a density less than that of fiber cement. The building material of claim 1, wherein the second component is fiber reinforced. The building material of claim 1, wherein one of the components at least partially surrounds the other component. The building material of claim 1, wherein the first component at least partially surrounds the second component. The building material of claim 1, further comprising a third component provided adjacent to the first component such that the first component is positioned between the second component and the third component. The building material of claim 1, wherein the individualized fibers have a planar orientation. The building material of claim 1, wherein the individualized fibers are oriented in the load direction. The building material of claim 1, wherein the fibers are oriented parallel to the fiber cement at the surface of the first component. The building material of claim 1, wherein the fiber cement of the first component comprises cellulose fibers. The building material of claim 1, wherein the fiber cement of the first component comprises natural inorganic fibers. The building material of claim 1, wherein the fiber cement of the first component comprises synthetic fibers. The building material of claim 1, wherein the fiber cement of the first component comprises engineering fibers. The building material of claim 1, wherein the second component is a lightweight material. The building material of claim 1, wherein the second component is a fire resistant material. The building material of claim 1 wherein the fiber cement of the first component is pressurized. The building material of claim 1 wherein the fiber cement of the first component is unpressurized. The building material of claim 1, wherein the fiber cement of the first component is formable. The building material of claim 1 wherein the fiber cement of the first component is embossed. The building material of claim 1, further comprising a sub layer to improve the bond between them between the first component and the second component. The building material of claim 1 wherein the second component is a lightweight core having a first side and a second side and the first component is a preformed fiber cement surface material on at least the first side of the core. The building material of claim 25, further comprising a second surface material on a second side of the core. The building material of claim 25, wherein the fiber cement surface material surrounds both the first and second sides of the core. The building material of claim 25, wherein the surface material has a thickness of less than about 3/16 ". The building material of claim 25, wherein the second surface material is made of a material selected from the group consisting of fiber cement, fibrous mats, paper, and polymer coatings. The building material of claim 25, wherein the core is cementitious. The building material of claim 25, wherein the core is solid. The building material of claim 25, wherein the core is open. The building material of claim 25, wherein the core is homogeneous. The building material of claim 25, wherein the core is heterogeneous. The building material of claim 25, wherein the core has a honeycomb structure. 27. The building material of claim 25, wherein the core comprises a plurality of perpendicularly facing corrugated core layers. The building material of claim 25, wherein the core comprises a horizontal single corrugated layer. The building material of claim 1, wherein the building material is a single plank. The building material of claim 1, wherein the building material is a trim board. The fiber cement component having a predetermined size and shape is preformed such that the fiber cement component is uncured and has a fiber content of about 5-12% by weight, wherein the fibers of this first component are preformed fiber cement layers Extending in a planar orientation parallel to the surface of; Molding a second component made of a curable material adjacent to the fiber cement component, wherein at least some of the components form mechanical and chemical bonds that interpenetrate; Curing at least a fiber cement component to form a building material while the fiber cement component is adjacent to the second component. 41. The method of claim 40, wherein the second component is made of a curable material. The method of claim 40, wherein the first component and the second component are cured simultaneously. The method of claim 40, wherein the first component and the second component are cured sequentially. 41. The method of claim 40 further comprising partially drying the fiber cement component after molding the second component but at least before curing the fiber cement component. 41. The method of claim 40, further comprising providing a fiber cement component on one side of the second component. 41. The method of claim 40, further comprising providing a third component adjacent to a second side of the second component. 47. The method of claim 46, wherein the third component is made of fiber cement. 41. The method of claim 40, wherein the fiber cement component has a thickness of less than about 3/16 ". 41. The method of claim 40, wherein the preformed fiber cement components comprise fibers aligned along the same plane. 41. The method of claim 40, wherein the fiber cement component comprises individualized fibers. 41. The method of claim 40, further comprising providing a fiber cement component at least partially surrounding the second component. 41. The method of claim 40, wherein the second component is made of a lightweight cementitious material. 41. The method of claim 40, wherein the second component is made of a refractory material. 41. The method of claim 40, further comprising molding the preformed fiber cement component to the desired shape while the component is in an uncured plastic state. delete

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